Maintaining muscle becomes increasingly important as we age.
Muscle supports much more than strength. It helps us move, remain physically active and maintain independence later in life.
Protein provides the amino acids our muscles need to maintain and rebuild muscle tissue.
But does that protein have to come from animal foods?
Animal protein is not the only option
Animal foods such as fish, eggs, dairy products, poultry and meat provide complete proteins containing all the essential amino acids.
Many plant foods also provide protein. These include soy foods, beans, lentils, peas, nuts, seeds and whole grains.
Recent evidence comparing plant and animal protein suggests that the difference is not as simple as “animal protein is better.”
Across randomized clinical trials, animal protein produced somewhat greater gains in muscle mass overall.
However, among adults aged 60 and older, there was no significant difference in muscle mass between plant and animal protein.
This means that maintaining muscle does not necessarily require animal protein.
The type of plant protein matters
Not all plant proteins are nutritionally identical.
Soy is particularly well studied. Across 17 randomized trials, soy protein produced similar effects on muscle mass to milk protein.
Evidence for other plant proteins is less extensive.
Plant proteins can differ in their amino acid composition and how easily their protein is digested and absorbed. This means that simply counting grams of protein does not always tell the whole story.
A varied diet can help provide a broader range of essential amino acids. Soy foods, legumes, nuts, seeds and whole grains can all contribute to daily protein intake.
Muscle needs more than protein
Protein is only one part of maintaining muscle.
Muscle also needs a reason to stay strong.
Regular resistance exercise — such as strength training using weights, resistance bands or body weight — provides the stimulus that helps maintain and build muscle tissue.
For healthy aging, the practical goal is therefore not to search for one “perfect” protein.
It is to consume enough protein from nutritious sources and combine good nutrition with regular resistance exercise.
